We will continue our studies of the electrophysiology of vision, recording the activity of individual receptor cells and neurons of the retina and optic ganglia in a variety of invertebrates and vertebrates. We will study receptor mechanisms, recording generator potentials and cell membrane conductance changes during stimulation by light, under various conditions, emphasizing the processes that affect the output of nervous activity by the receptor and its role in the processing of visual information. We will study the mechanisms and dynamics of interaction in the retina and optic ganglia, recording the activity of several individual cells simultaneously in response to combined temporal and spatial patterns of retinal illumination. We will use multiple-unit as well as single unit recording, with computer acquisition and analysis, and extend our theoretical interpretation of the results. We seek to analyze the mechanisms whereby the interplay of excitation and inhibition in retinal and ganglionic networks molds the patterns of neural activity in response to form, motion, color, etc. in the visual environment. Our aim is the understanding of integrated visual function in terms of the properties and mechanisms of the cellular units of the visual system, and their interactions. BIBLIOGRAPHIC REFERENCES: Dodge, F.A. and Kaplan, E.: Visual Fields in the Limulus Eye, Biophys. J. 15, 172a, 1975. Kaplan, E. and Dodge, F.A.: Receptive Fields of Ommatidia in the Limulus Eye, Neuroscience Abstracts, 5th Annual Mtg. 1975, p. 115.